In the old days, when many medicines were taken in liquid form, chemist’s shops advertised themselves with large glass jars filled with brightly coloured liquids. The medicines they sold were often coloured too, but whether this actually made any difference to their effectiveness is debateable. However, older physicians thought so and many patients were convinced.

Something that colour certainly did help with was identification. Doctors assisting patients with repeat prescriptions could ask “Which colour medicine have you been taking?” A recent study suggests this is an issue still relevant today.

Of course, these days we have become more sophisticated. Your doctor should provide you with the names of the medicines you are taking, and doctors and pharmacists keep considerably better records. But the number of effective medicines has grown enormously over the past 50 years – so much so that the need for identification has increased. One way of doing this has been to use colour. Indeed, there is a psychology of colour which the marketing industry takes advantage of.

But we all know this is just superficial. It should make no difference to us if our tablets change colour. Right?

A recent study looked at patients with epilepsy. This is a condition where regularly taking the prescribed medicine is particularly important both for everyday living and, in some cases, for being allowed to drive. Yet 1.2% had stopped taking their medication. That might seem a low percentage – and we do not know how long they stopped for – but it is a result with serious implications.

The researchers carefully compared more than 11,000 patients who had stopped their medication with 50,000 others who hadn’t and looked for reasons why. It turned out that one reason was a change in colour and/or shape of the tablets. About one-third of the patients who stopped had been changed to the same anti-epileptic medication but with a different appearance.

It is increasingly common for people on repeat prescriptions for all types of ailment to see a change in the colour of their tablets. Often, this is because a branded product is replaced by a cheaper equivalent that does exactly the same – so called ‘generic prescribing’. This can happen when the patent taken out by the company that discovered the medicine runs out and other companies can start marketing an identical product. With the constant need to keep medical costs to a minimum, doctors and pharmacists are expected to provide patients with the cheapest form of the medicine.

This can often mean that patients who have been taking a coloured tablet for some time suddenly find they have been given a white or off-white tablet in its place. Unless their doctor or pharmacist has explained what’s going on, they may become suspicious that they’re not getting the same medication – and sometimes stop taking it.

Often, it can then take some time before they tell their doctor about this or it’s discovered they are no longer taking the tablets. Sometimes this can be of great importance.

The study brings home how important it is that doctors and pharmacists carefully explain to patients any changes in the appearance of their medicines and reassure them they are still getting the same effective treatment.

And if you or a family member sees a change in the appearance of tablets you are taking, don’t be surprised and don’t stop the treatment, but go and ask your pharmacist or doctor about it if you are at all concerned.